Add badge for integration tests

Signed-off-by: Matheus Pimenta <matheuscscp@gmail.com>

Author: matheuscscp

README.md

@@ -1,5 +1,7 @@
 # sumoapi-go
 
+[![Test Integration](https://github.com/sumo-mcp/sumoapi-go/actions/workflows/test-integration.yaml/badge.svg)](https://github.com/sumo-mcp/sumoapi-go/actions/workflows/test-integration.yaml)
+
 A Go SDK for https://sumo-api.com.
 
 ### Disclaimer